Orthopaedic shoes



United States Patent Hilkka O. Hormavirta 86 Bloor St. W., Toronto,Ontario, Canada [21] Appl. No. 696,437

[22] Filed Jan. 8,1968

[45] Patented Dec. 1, 1970 [72] Inventor [54] ORTHOPAEDIC SHOES 6Claims, 3 Drawing Figs.

[52] US. Cl 128/581, 1 28/621 [51] 1nt.Cl A61f5/14 [50] Field ofSearch128/581,

[56] References Cited UNITED STATES PATENTS 1,845,031 2/1932 Arthur128/581 Primary Examiner-Adele M. Eager Assistant Exam iner-J YaskoAttorneyMaybee and Legris ABSTRACT: An orthopaedic shoe has a retainingstrap. When the shoe is fitted to the foot the strap is secured to theinner edge of the sole directly below the ankle joint and extendsoutside the upper diagonally over the top of the forefoot, and issecured at the other end to the outer edge of the sole adjacent to thejoint of the fifth toe, thus providing a brake against the downwardthrust of the soleus at the upper end of the longitudinal arch.

Patented Dec. 1, 1970 3,543,764

INVEN'IOR. HILKKA O. HORMAVI RTA ATTORNEYS ORTHOPAEDIC SHOES It iscommon to find footwear with crossed or uncrossed retaining straps, theobjective of which is the securing of the footwear on the foot andpreventing the foot from sliding on the sole of the footwear. V

The oldest model dates back to antiquity and some variation or other ofit is still the mostcommon footwear in the world today. It isessentially a sandal in which the upper ends of the longitudinal strapsare attached upon the outer edges of the upper part of the sole oneither side at varying distances from the toe of the sandal. Thesestraps cross over the top of the forefoot to the opposite side to fastenby their lower ends to the sole near to or upon the heel section of thesole of the sandal. A further strap may or may not be present whichconnects the longitudinal straps by a strap which curves behind theheel. The object of the heel strap is to further secure the heel sectionof the sole of the sandal to the foot.

It is also common to find shoes with uppers in which the retainingstrap(s) are attached at varying points along the inner sole or morecommonly as extension straps of the inner wall of the upper which crossover the top of the forefoot to fasten by some device to a counter strapfrom the outer sole or as an extension of the outer wall of the upper.Or the strap may be extensible which obviates the necessity of afastening device.

My invention is an improved retaining strap which supplements theinherent tensile braking tendons of the foot itself.

Be it said that all retaining straps and uppers of shoes have functionedto a degree as supplementary brakes without being designed to serve thatfunction. This effect is incidental or accidental. There has been noassured consistency nor adequacy of this function by any footwear. Theessence of my invention is the specific construction and arrangement ofa retaining strap which provides tensile braking action of assureddegree and quality. The action and effects ofa strap attached accordingto my specification can only be appreciated by understanding thedynamics of the foot and the action of its inherent tensile brakingtendons.

The optimal, i.e. the most nearly physiological, course of the foot inwalking has been established. It does not proceed on a straight forwardhorizontal plane from heel to toe, rather it follows a double zigzagforward torquing course, beginning at the back of the heel, outward anddownward along the outer plantar surface of the heel followed by areversing torque through the ankle and tarsals to the inner longitudinalarch at the upper end of which it is again given a reverse torqueoutward to continue through the long axis of the first toe and fanningminimally through the lateral four toes.

Achievement of this optimal course is dependent upon the adequatelyphased correction of the momentum and direction set into motion bygravity arid the power of the prime propulsion muscle of the calf thesoleus -through feedback from pressure, tension and stretch sensors inmuscles and tendons to the inherent tensile braking tendons ofthe foot.

The overall momentum and direction of this course is determined byrelationship between the direction of the gravitational fall of thesuperimposed body weight and the power and action of the main propulsionmuscle (soleus). The anatomic arrangement of this muscle is such that itelevates the outer half of the heel producing an inward and downwardtorque in the direction in which the weight load is transmitted throughthe ankle and tarsals and through them to the outer side of the heel ofthe opposite foot.

For the sake of description of the inherent braking tendons the aboveoutlined optimal course will be considered as consisting of threedistinctly separate phases whereas in reality they flow one into theother, beginning at the heel.

The first phase consists of the outward and downward torquing motionfrom the back of the heel along its outer plantar surface. The momentumof this phase is derived from the shift of the body weight towards theoutsideof one foot and from the active thrust of the soleus of theopposite foot. The main tendons which brake this motion are three innumber, one of which is suspensory cable circling under the undersurface of the outer ankle bones, the others are tensile but notsuspensory tendons.

The second phase consists of the reversing torque through the ankle andtarsals to the longitudinal arch. The momentum of this phase is derivedfrom the gravitational shift of the weight to fall on the back of theheel of the opposite foot and from the onset of the contraction of thesoleus of the foot in question. The main tendons which brake this motionare also three in number, all of which are suspensory cables whichcircle under the undersurface of the inner ankle bone and under theundersurface of the lower arch and toe bones. By the end of this secondphase most of the weight has been transferred to the opposite foot.

The third phase consists of the outward torquing which begins at theupper end of the longitudinal arch and then continues along the lengthof the metatarsal to the first toe and through its long axis to the padat its tip and through the lateral metatarsal heads to the pads on thetips of the lateral four toes. The momentum at this phase is chieflyderived from muscle power and not from gravity. The power thrust isgenerated by the continuing contraction of the soleus to which is addedthe thrusting power of the muscles involved in pressing the pads of thetoes to the ground. To obtain the maximal pushoff through the pads ofthe toes the correct alinement of the upper part of the longitudinalarch is essential. In detail the critical area consists ofthe joint areabetween the upper end of the central bone of the longitudinal arch (themedial cuneiform) and the lower end of the first metatarsal themetatarso-cuneiform joint. This critical area is not provided with asuspensory brake of the nature of those in the lower part of the foot asthe weight-sustaining factor is scarcely required, the weight havingbeen largely transferred to the opposite foot. It is, however, providedwith a relatively small tensile torquing muscle the tibialis anticus.The tendons of this muscle are thin and so attached that they cansustain but a minimum of stretch, only sufficient to trigger thefeedback to initiate the alining countertorque but not sufficient toadequately sustain the inward and downward torque of the soleus thrust.

My invention is primarily concerned with supplying this critical,inherently weak area with a synthetic tensile brake against the powerthrust of the soleus to support the tibialis anticus in its aliningfunction.

While the strap is designed to exert the maximal effect at themetatarso-cuneiform joint its braking action begins farther back at theankle thus it acts as a supplementary brake to the suspensory tendons ofthe ankle as well.

To ensure that the strap exerts the optimal braking effect at themetatarso-cuneiform joint correct obliquity of its course must beadhered to. The correct obliquity is obtained by its attachment to thesole according to my invention.

In a shoe with an enclosed upper the usual reinforcements of the outerand inner walls of the heel section of the upper are usually sufficientto supplement the tensile braking action of the ankle cradling tendonsof phases one and two. In transition to and during the third phase theusual inner wall of the upper does not supply the required, i.e. thecorrect, tensile brake for the above-described weak area. My inventionis designed to perform this function in a shoe with an enclosed upper.

It consists of a shoe having a strap which is so attached as to phase ina braking action against the inward and downward thrust of the soleussufficient to prevent over stretching the tibialis anticus, permittingfeedback from pressure tension and stretch sensors to stimulate thenecessary muscle contraction which alines the joint in preparation forthe recruitment of the thrust muscles of the toes.

The invention is hereinafter more particular described and isillustrated in the annexed drawings in which:

FIG. 1 is a view of the inner side of a shoe made in accordance withthis invention showing the bones of the foot in fine lines;

FIG. 2 is a view of the other side of the shoe shown in FIG. 1; and

FIG. 3 is a plan view of the shoe shown in FIG. 1.

In the drawings corresponding numerals refer to corresponding parts inthe various views.

The shoe comprises a sole 1 and an upper 2. The sole 1 has a raised heelportion 3. The upper comprises a toe portion and a heel portion andencompasses the foot below the ankle. The sole, heel and upper may bemade of leather or other suitable material.

A strap 4 embraces the foot of the wearer. The strap may be formed ofleather, plastic, canvas, or other pliant but substantiallynonexpansible material. As shown in FIG. 1, the strap is secured at oneend at the outer edge of the sole immediately in front ofa line Aperpendicular to the lower (posterior) margin of the ankle joint 5 whenthe shoe is fitted on the foot. As shown in FIG. 3, the strap extendsoutside the upper, diagonally over the top of the forefoot above themetacarpocuneiform joint 6, and is secured to the inner edge of the soleof the shoe opposite the metatarso-phalangeal joint 7 of the fifth orlittle toe, as shown in FIG. 2. This is the joint where the little toeattaches to the forefoot. The strap is of such strength, width, andlength that it firmly engages the foot over a substantial area andprovides a braking action against the inward and downward thrust of thesoleus at the medial metatarso-cuneiform joint sufficient to enable thetibialis anticus to come into play to aline the joint in preparation forthe recruitment of the thrust muscles of the toes.

Preferably the strap 4 is formed in two parts connected by a lacing orbuckle 8, or other securing means, which is adjustable whereby thetension of the strap can be varied.

The width of the strap must be such that it will firmly embrace the footwithout cutting into the flesh. In practice the width of the strapshould be not less than one-quarter of an inch. The strap may be uniformin width, but preferably on the inner side of the shoe it is flared asshown in the drawings and secured to the sole along a line from thepoint of heel attachment to a point about one-half of an inch heelwardfrom the first metatarso-phalangeal joint 9 (the joint where the big toeattaches to the forefoot).

The strap is separate from the upper although it may be attached to it.The strap is secured to the sole by a line of stitching 10 on the insideof the shoe and 11 on the outside of the shoe. The length andproportions of the strap must be such as to give the desired support tothe foot of the wearer and in many cases the shoe and strap must bespecially fitted or made to order for the wearer. However, standardsizes may be produced and used by persons whose feet are of standardsize and configuration, particularly when the strap is provided with anadjustable fastener, whereby the length of the strap may be adjusted soas to engage the foot with the required supporting action.

No details of the construction of the shoe or of the method of securingthe strap to the shoe are shown since these are ordinary shoemakingpractices. Instead of having the strap sewn directly to the sole, it maybe secured to the sole through the intermediary of the upper. Likewise,the strap and the upper may be secured or sewn together at any pointwhere the strap overlaps the upper.

I claim:

I. A shoe having a sole, an upper, and a plaint but substantiallynonexpansible strap secured at one end on the inner edge of the soleimmediately in front ofa line perpendicular to the lower (posterior)margin of the ankle joint when the shoe is fitted on the foot, andextending separate from and outside the upper diagonally over the top ofthe forefoot above the metacarpo-cuneiform joint and secured at theother end to the outer edge of the sole opposite themetatarso-phalangeal joint of the fifth toe (the joint where the littletoe attaches to the forefoot), said strap being of such strength, width,and length that it firmly engages the foot over a substantial area andprovides a braking action against the inward and downward thrust of thesoleus sufficient to enable the tibialis anticus to come into play toaline the joint in preparation for the recruitment of the thrust musclesof the toes. I

2. A shoe constructed as clalmed in claim 1 In which the strap on theinner side of the shoe is flared and secured to the sole along a linefrom the point of the heel attachment to a point about one-half inchheelward from the first metatarsophalangeal joint (the joint where thebig toe attaches to the forefoot).

3. A shoe constructed as claimed in claim I, in which the strap isformed of two parts provided with means for securing the parts together,which securing means are adjustable whereby the tension ofthe strap maybe varied.

4. A shoe constructed as claimed in claim 2, in which the strap isformed of two parts provided with means for securing the parts together,which securing means are adjustable whereby the tension of the strap maybe varied.

5. A shoe constructed as claimed in claim I in which the strap is formedpartially of the upper.

6. A shoe constructed as claimed in claim 1 in which the strap issecured to the sole through the intermediary of the upper.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION patent 3,543,764Dated December 1 1970 Hilkka O. Hormavirta Inventor(s) It is certifiedthat error appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

Column 4 line 12 "plaint" should read pliant Signed and sealed this 13thday of April 1971.

(SEAL) Attest:

WILLIAM E. SCHUYLER, J1

EDWARD M.FLETCHER,JR.

Commissioner of Patent Attesting Officer

